Viscosimeter



Feb. 9, 1954 w, PETERSON 2,668,441

VISCOSIMETER Filed June 2, 1949 IN VEN TOR. W. M. PETERSON ATTORNEYPatented Feb. 9, 1954 UNITED STATES PATENT OFFICE 2 Claims.

The present invention relates to improvements in viscosimeters and hasreference to improvements for increasing the accuracy of measurementrather than any improvement in the fundamental viscosimetercharacteristics.

- Various viscosimeters which have been in wide useage are based uponthe use of a stopper inserted in an opening below the orifice of theinstrument. This has lead to large errors, particularly with lowviscosity fluids, since some of the fluids will frequently pass throughthe orifice into the chamber between the orifice and the stopper. Whenthe stopper is pulled, this portion of the fluid will pass into themeasuring receiver without passing through the orifice during themeasured time. Furthermore, timing of the pulling of such a stopperleads, likewise, to major errors.

Among the objects of th present invention are the provision of improvedviscosimeters; the provision of viscosimeters having means forinitiating flow through the orifice with exactitude, the provision ofviscosimeters in combination with time-registering means, and suchfurther objects, advantages, and capabilities as will hereafter appearand as are inherent in the construction disclosed herein. My inventionfurther resides in the combination, construction, and. arrangement ofparts illustrated in the accompanying drawings and, while I have showntherein what is now regarded as the preferred embodiment of thisinvention, I desire the same to be understood as illustrative only andnot to be interpreted in a limiting sense.

In the drawings annexed hereto and forming a part hereof,

Fig. 1 is a schematic diagram, partially in vertical section;

Fig. 2 is a plan of the viscosimeter; and

Fig. 3 represents a section taken substantially along the planeindicated by the line 3-3, Fig. 1.

viscosimeters in accordance herewith are provided with an orificeclosure at the upper end of the orifice within the reservoir. Commonoperating means are provided both to initiate flow through the orificeby lifting the closure and to start a time register.

The viscosimeter hereof includes a viscosimeter tube 4 which has aconical lower inner surface. Centrally of the lower end, the tube 4carries a press fit insert 5 which has an opening 5 therethrough ofcalibrated size. Plugs of the same sizes but having openings ofdifferent sizes may be provided for use with fluids of differentviscosities. The tube 4, further, is provided with a hollow boss 1 whichextends through and is secured in a wall of a temperature-controllingjacket 8. The tube 4 is provided, at a level just below its open upperend 9, with an outwardly projecting flange l0 which has a circular wallI l rising therefrom. The flange l0 and Wall ll form an overflowcontainer to receive excess fluid placed in the tube 4. The circularwall H fits into a circular opening in the upper wall of the jacket 8,to maintain the tube 4 in alignment.

A circular plate I2 rests on and fits within the upper edge of the wallH, being provided with openings I-4 through which to insert a stirrerand thermometer into the tube 4, and with an opening [5 in alignmentwith the overflow container about the tube 4. By means of the openingl5,a syringe or pipette may be inserted into the overflow container toremove excess liquid and ensure that the operating head of theviscosimeter is exactly at the upper end of the tube 4. Having the topof the fluid at the edge 9 of the tube 4 ensures that the initialhydrostatic height of the liquid above the orifice 6, at the time ofstarting the fluid flow, is always constant.

.An operator is mounted on the plate l2 to initiate flow from theviscosimeter. A typical example of such an operator is constituted by apair of mounting posts It of brass or other magneticallynon-responsivematerial. A pair of solenoids I! are mounted upon posts 46. Thesolenoids I! are provided with conventional soft iron core l8, which arin magnetic contact at their upper and lower ends with magnetizableplates [9 and 20 which interconnect the solenoid cores l8. Between thesolenoids ll, a nonmagnetic tube 2| is secured in plates [9 and 20, withits lower end open and its upper end closed by an extension from theupper magnetizable pole piece. Whereas most tandem mounted solenoids arewound in opposite sense, whereby lines of flux flow successively throughthe two, it should be understood that the present tandem mounting is notof this sort. In this typical example, the direction of winding of thecoils is such that the polarity of the corresponding coil ends is thesame. With this arrangement, the plunger 24 forms a bridge common to thetwo coils. The solenoids are suitably wound and connected'in the sensestated and provided with conventional contacts 22, 23. This constructionmay be replaced by a single solenoid suitably constructed and placed.The electromagnet is of such a nature that the residual magnetismdescribed above retains the valve in open posi-,

tion thereby obviating the necessity of keeping th key depressed duringthe flow of fluid.

A plunger 24 is provided for sliding within the tube 2|. This plunger 24is of a steel such that it is a semipermanent magnet. Thus, when theelectromagnet is energized, the plunger 24 moves into contact with adownward extension from the central part of the upper pole piece 20. Theresidual magnetism of the plunger 24 will maintain the plunger inactuated or raised position. While the plunger 24 has been described asa semipermanent magnet and the remainder of the metal in the magneticcircuit as soft or nonpermanent iron, all that is necessary is that someportion of the metal in the circuit be at least semipermanent. Thus, theplunger maybe of soft iron and either plate I9-or or one or both of thesolenoid cores lfl'may be of magnetic or semipermanent magneticmaterial.

The solenoid is so mounted that the plunger 24 is positioned axially ofthe tube 4. A valve rod 25 is secured in the lower end of the plunger24. A valve 28 is secured to the lower end of the rod 25. The lowersurface of valve 26 is shaped to contact the lower inner wall of thetube 4, which may be of any suitable shape, whereby, when the plunger24, rod 25, and valve 26 assembly is in lowered position, the valve willseat accurately and close the opening 6 tothe passage of fluid.

If desired, a hanging eye 2'! may be secured to the-pole piece 20wherewith to suspend the viscosimeter structure, just described.

A starter and timer is shown in the lower left portion of Fig. 1. Thisconsists of a lever mounted on a pivot 28 in a cabinet 29. One arm 30 ofthe lever extends horizontally within the cabinet. A springtl, inengagement with the lever, moves the arm 38 upwardly into normalposition of the spring. A key 32 is connected'to the free end of the arm38 for moving the arm downwardly upon depression of the key. A switchcontact 33 is secured to the free end of the arm 38 and is in electricalcontact with the circuit line 3%. A second switch contact 35 is mountedin the cabinet and is in electrical contact with a circuit line 38. Upondepressing the key 32, contacts 33 and 35 engage to close the switch.

The lever in the cabinet 29 is provided with a second arm 31 whichextends upwardly out of the cabinet. Movement of the key 32 brings-thelever arm 31 into operative engagement with a time register, such as astop watch 38 to effect starting and stopping of the register uponsuccessive depressions of the key. Any suitable time register,electrical or mechanical, may be employed which can be started orstopped by successive operation of the key. In order to be able toproduce substantially simultaneous op eration of the switch and thestarting of the timer, the crank arm 51, shown in Fig. 1, may have anadjustable pin for actuating the timer stem, as shown, or one of theelectrodes 33, 35 may be made adjustable.

Circuit lines 3 3 and 36 are connected wit contacts 23 and 22, and witha battery 39, or other source of direct current in the circuit.

In operation, a cork is first put into the opening in the bottom of thetube d, with the operator removed, and then the fluid to be tested ispoured into the tube until it reaches a height above the tube 4. Duringfilling of the tube 4,1

the corkis kept in the hollow boss I, but it is not employed to startthe flow of fluid through the orifice.

After the tube 4 has been filled and the valve member 26 and itsoperating structure have been put in place, the temperature of the fluidis brought to any desired degree by means of the controlled bathtemperature. A suitable thermometer and a stirring disk are inserted inan opening l4. When the temperature is correct in the tube 4, thethermometer and stirring disk are removed. Then the cork 40 is removedand a standard receiver is placed close to the discharge opening. Next,the excess fluid around the upper end 9 of the tube 4 is removed by apipette or other suitable instrument. They key 32 is then tapped andthis starts the timer 38 and momentarily closes the switch 33, 35 so asto cause the valve member 26 to rise to its fixed upper limit of motion,thus starting the flow of fluid through the orifice at zero time on thetimer"38-. When the fluid height in the receiver reaches the hairline,the key is tapped again and this stops the running .of the :timer. Italso sends an impulse through the coils H, but this second impulsethrough'the coils is oi'no consaquence. The tapping motion given tothekey, as described, is of significance in affording a; convenience ofmanipulation at the start of the timing and at theend thereof, and inreducingpersonal error in timing the transit ofthehairline at the end ofthe test. The receivers in common use have a sufficient capacity to-holdall of the fluid in the tube 4.

It is of course understood that the specific description of structureset forth above may be departed from without departing from the spiritof this invention as described in this specification and as defined inthe appended claims.

Having now described my invention, 1 claim:

1. A viscosimeter comprising a vertical container for liquid to betested, there being an orifice in the lower end thereof, a circularplate in the form of a ring-like part connected to the peripheralportion of the upper end of said con-- tainer and having a pair ofmounting'postscar ried by said plate, a pair of solenoids mounted inlaterally spaced relation on the upper ends of said posts, elongatedupper and lower pole pieces, the lower pole piece crossing'theopening insaid ring-likepart, leaving two'openings ateach side of the lowerpolepiece, the spacing between said solenoids being sufficient to have thesolenoids clear said two openings, whereby the latter are accessiblefrom points substantially directly above, thereby readily accommodatingin said container, a valve controlling said orifice,

an electrical solenoid controlling said valve, 2.

stop watch support, a stop watch mounted on said support, a bell crankpivoted thereon and including an arm for controlling said watch, a

second arm on said bell crank, contact means carried by said-second arm,a spring connected with said second arm for moving the latter in.

a direction to open said contact means, a manually actuable partconnected with said second arm for moving the latter against the actionof said spring to momentarily close said contacts,

and circuit means connected between said contact means and saidsolenoid, whereby said solenoid is operated substantially simultaneouslywith the starting and stopping of the watch, said solenoid being soconstructed and arranged that the residual magnetism is suflicient tohold said valve open, said watch being stopped by a second actuation ofsaid manually actuable part.

WESLEY M. PETERSON.

References Cited in the file of this patent UNITED STATES PATENTS NameDate Courtois Apr. 25, 1905 Number Number 6 Name Date Kahrs May 20, 1913Saybolt Mar. 23, 1915 Teschner May 20, 1931 Fairbairn June 14, 1932Thomas Aug. 24, 1937 Fairbairn Mar. 14, 1939 Von Stoeser et al. July 31,194 MacDonald Apr. 29, 1950

